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60-401: The life-cycle of dry rot can be broken down into four main stages. Dry rot begins as a microscopic spore which, in high enough concentrations, can resemble a fine orange dust. If the spores are subjected to sufficient moisture, they will germinate and begin to grow fine white strands known as hyphae . As the hyphae grow they will eventually form a large mass known as mycelium . The final stage

120-457: A megasporangium that produces megaspores or a microsporangium that produces microspores. In flowering plants, these sporangia occur within the carpel and anthers, respectively. Fungi commonly produce spores during sexual and asexual reproduction. Spores are usually haploid and grow into mature haploid individuals through mitotic division of cells ( Urediniospores and Teliospores among rusts are dikaryotic). Dikaryotic cells result from

180-414: A multicellular gametophyte , which eventually goes on to produce gametes. Two gametes fuse to form a zygote , which develops into a new sporophyte. This cycle is known as alternation of generations . The spores of seed plants are produced internally, and the megaspores (formed within the ovules) and the microspores are involved in the formation of more complex structures that form the dispersal units,

240-492: A building can be an extremely serious infestation that is hard to eradicate, requiring drastic remedies to correct. Significant decay can cause instability and cause the structure to collapse. The term dry rot , or true dry rot , refers to the decay of timbers from only certain species of fungi that are thought to provide their own source of moisture and nutrients to cause decay in otherwise relatively dry timber. However, there has been no published experimental evidence to support

300-437: A center pole. This shows that four spores shared a common origin and were initially in contact with each other forming a tetrahedron. A wider aperture in the shape of a groove may be termed a colpus . The number of colpi distinguishes major groups of plants. Eudicots have tricolpate spores (i.e. spores with three colpi). Envelope-enclosed spore tetrads are taken as the earliest evidence of plant life on land, dating from

360-417: A distinction between logical paradoxes and semantic paradoxes, with Russell's paradox belonging to the former category, and the liar paradox and Grelling's paradoxes to the latter. Ramsey introduced the by-now standard distinction between logical and semantical contradictions. Logical contradictions involve mathematical or logical terms like class and number , and hence show that our logic or mathematics

420-425: A paradox that questions whether a ship repaired over time by replacing each and all of its wooden parts one at a time would remain the same ship. Paradoxes can also take the form of images or other media. For example, M.C. Escher featured perspective-based paradoxes in many of his drawings, with walls that are regarded as floors from other points of view, and staircases that appear to climb endlessly. Informally,

480-595: A putrid odour, for dispersal of fungal spores is yet another strategy, most prominently used by the stinkhorns . In Common Smoothcap moss ( Atrichum undulatum ), the vibration of sporophyte has been shown to be an important mechanism for spore release. In the case of spore-shedding vascular plants such as ferns, wind distribution of very light spores provides great capacity for dispersal. Also, spores are less subject to animal predation than seeds because they contain almost no food reserve; however they are more subject to fungal and bacterial predation. Their chief advantage

540-431: A result that appears counter to intuition , but is demonstrated to be true nonetheless: A falsidical paradox establishes a result that appears false and actually is false, due to a fallacy in the demonstration. Therefore, falsidical paradoxes can be classified as fallacious arguments : An antinomy is a paradox which reaches a self-contradictory result by properly applying accepted ways of reasoning. For example,

600-465: A statement can contain a contradiction without being a paradox. "This statement is written in French" is an example of a contradictory self-referential statement that is not a paradox and is instead false. Another core aspect of paradoxes is non-terminating recursion , in the form of circular reasoning or infinite regress . When this recursion creates a metaphysical impossibility through contradiction,

660-697: A zygote before developing further. The main difference between spores and seeds as dispersal units is that spores are unicellular, the first cell of a gametophyte, while seeds contain within them a developing embryo (the multicellular sporophyte of the next generation), produced by the fusion of the male gamete of the pollen tube with the female gamete formed by the megagametophyte within the ovule. Spores germinate to give rise to haploid gametophytes, while seeds germinate to give rise to diploid sporophytes. Vascular plant spores are always haploid . Vascular plants are either homosporous (or isosporous) or heterosporous . Plants that are homosporous produce spores of

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720-433: Is Russell's paradox , which questions whether a "list of all lists that do not contain themselves" would include itself and showed that attempts to found set theory on the identification of sets with properties or predicates were flawed. Others, such as Curry's paradox , cannot be easily resolved by making foundational changes in a logical system. Examples outside logic include the ship of Theseus from philosophy,

780-475: Is a fruiting body which pumps new spores out into the surrounding air. In other fields, the term has been applied to the decay of crop plants by fungi. In health and safety , the term is used to describe the deterioration of rubber , for example the cracking of rubber hoses. Dry rot is the term given to brown rot decay caused by certain fungi that deteriorate timber in buildings and other wooden construction without an apparent source of moisture. The term

840-404: Is a misnomer because all wood decaying fungi need a minimum amount of moisture before decay begins. The decayed wood takes on a dark or browner crumbly appearance, with cubical like cracking or checking, that becomes brittle and can eventually crush the wood into powder. Chemically, wood attacked by dry rot fungi is decayed by the same process as other brown rot fungi. An outbreak of dry rot within

900-438: Is a specific example of the more general observation of the butterfly effect , or that a time-traveller's interaction with the past—however slight—would entail making changes that would, in turn, change the future in which the time-travel was yet to occur, and would thus change the circumstances of the time-travel itself. Often a seemingly paradoxical conclusion arises from an inconsistent or inherently contradictory definition of

960-728: Is a statement that, despite apparently valid reasoning from true or apparently true premises, leads to a seemingly self-contradictory or a logically unacceptable conclusion. A paradox usually involves contradictory-yet-interrelated elements that exist simultaneously and persist over time. They result in "persistent contradiction between interdependent elements" leading to a lasting "unity of opposites". In logic , many paradoxes exist that are known to be invalid arguments, yet are nevertheless valuable in promoting critical thinking , while other paradoxes have revealed errors in definitions that were assumed to be rigorous, and have caused axioms of mathematics and logic to be re-examined. One example

1020-399: Is found, plaster and wall coverings should be stripped back to a metre past the infestation in all directions and the whole area treated. However, given that dry rot attacks only wet timber, common sense should dictate that plaster need not be removed where there is no timber or any timber is dry (outside the zone of wetting that caused the outbreak). Identifying the source of water and allowing

1080-400: Is inhibited, but it can stay dormant at relative humidities down to 76 percent. These relative humidities correspond to equilibrium moisture contents of wood of 19 and 15 percent, respectively. It is to be remembered that most forms of rot cannot be stopped. An explanation of the term "dry rot" circles around boatyards periodically. In the age of wooden ships, boats were sometimes hauled for

1140-531: Is known to be true, then it can be inferred that it must be false. Russell's paradox , which shows that the notion of the set of all those sets that do not contain themselves leads to a contradiction, was instrumental in the development of modern logic and set theory. Thought-experiments can also yield interesting paradoxes. The grandfather paradox , for example, would arise if a time-traveler were to kill his own grandfather before his mother or father had been conceived, thereby preventing his own birth. This

1200-406: Is not in my vocabulary") or rely on hasty assumptions (A father and his son are in a car crash; the father is killed and the boy is rushed to the hospital. The doctor says, "I can't operate on this boy. He's my son." There is no contradiction, the doctor is the boy's mother.). Paradoxes that are not based on a hidden error generally occur at the fringes of context or language , and require extending

1260-579: Is problematic. Semantical contradictions involve, besides purely logical terms, notions like thought , language , and symbolism , which, according to Ramsey, are empirical (not formal) terms. Hence these contradictions are due to faulty ideas about thought or language, and they properly belong to epistemology . A taste for paradox is central to the philosophies of Laozi , Zeno of Elea , Zhuangzi , Heraclitus , Bhartrhari , Meister Eckhart , Hegel , Kierkegaard , Nietzsche , and G.K. Chesterton , among many others. Søren Kierkegaard, for example, writes in

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1320-456: Is repeatedly wetted. Diffusion of these toxic compounds out of the wood, and into surrounding soils and plants is not appropriate from a toxicity or environmental standpoint, and these types of treatment are not recommended for wood in-service. Certain copper compounds, such as copper naphthenate , are available as a brushable solution and are frequently used when dry-rot damage is repaired by splicing in new wood; after removal of bulk rotten wood

1380-478: Is that spores were an adaptation of early land plant species, such as embryophytes , that allowed for plants to easily disperse while adapting to their non-aquatic environment. This is particularly supported by the observation of a thick spore wall in cryptospores . These spore walls would have protected potential offspring from novel weather elements. The second more recent hypothesis is that spores were an early predecessor of land plants and formed during errors in

1440-451: Is that, of all forms of progeny, spores require the least energy and materials to produce. In the spikemoss Selaginella lepidophylla , dispersal is achieved in part by an unusual type of diaspore , a tumbleweed . Spores have been found in microfossils dating back to the mid-late Ordovician period. Two hypothesized initial functions of spores relate to whether they appeared before or after land plants. The heavily studied hypothesis

1500-506: Is written in English" is a true and non-paradoxical self-referential statement), self-reference is a common element of paradoxes. One example occurs in the liar paradox , which is commonly formulated as the self-referential statement "This statement is false". Another example occurs in the barber paradox , which poses the question of whether a barber who shaves all and only those who do not shave themselves will shave himself. In this paradox,

1560-476: The Philosophical Fragments that: But one must not think ill of the paradox, for the paradox is the passion of thought, and the thinker without the paradox is like the lover without passion: a mediocre fellow. But the ultimate potentiation of every passion is always to will its own downfall, and so it is also the ultimate passion of the understanding to will the collision, although in one way or another

1620-535: The Grelling–Nelson paradox points out genuine problems in our understanding of the ideas of truth and description. Sometimes described since Quine's work, a dialetheia is a paradox that is both true and false at the same time. It may be regarded as a fourth kind, or alternatively as a special case of antinomy. In logic, it is often assumed, following Aristotle , that no dialetheia exist, but they are allowed in some paraconsistent logics . Frank Ramsey drew

1680-534: The etymological fallacy that dry rot requires less or no water than other species that use the brown rot decay mechanism. The (London) Times on Tuesday 12 March 1793 carried an advertisement that informs the reader that the "British Colour Company, No. 32, Walbrook, London continues to use, manufacture and sell paints prepared with the Oil of Coal, which is of a very penetrating nature, and hardens wood in an uncommon degree protecting it from weather, dry rot and ice". In

1740-455: The life cycles of many plants , algae , fungi and protozoa . They were thought to have appeared as early as the mid-late Ordovician period as an adaptation of early land plants. Bacterial spores are not part of a sexual cycle, but are resistant structures used for survival under unfavourable conditions. Myxozoan spores release amoeboid infectious germs ("amoebulae") into their hosts for parasitic infection, but also reproduce within

1800-491: The meiosis of algae , a hypothesized early ancestor of land plants. Whether spores arose before or after land plants, their contributions to topics in fields like paleontology and plant phylogenetics have been useful. The spores found in microfossils, also known as cryptospores, are well preserved due to the fixed material they are in as well as how abundant and widespread they were during their respective time periods. These microfossils are especially helpful when studying

1860-408: The seeds and pollen grains. The term spore derives from the ancient Greek word σπορά spora , meaning " seed , sowing", related to σπόρος sporos , "sowing", and σπείρειν speirein , "to sow". In common parlance, the difference between a "spore" and a " gamete " is that a spore will germinate and develop into a sporeling , while a gamete needs to combine with another gamete to form

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1920-464: The affected timbers to dry will kill dry rot, as it is a fungus and requires water as all fungi do. This will not, however, kill any spores left behind, which will remain viable and cause the rot to return upon wetting. Spore In biology , a spore is a unit of sexual (in fungi) or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of

1980-423: The barber is a self-referential concept. Contradiction , along with self-reference, is a core feature of many paradoxes. The liar paradox, "This statement is false," exhibits contradiction because the statement cannot be false and true at the same time. The barber paradox is contradictory because it implies that the barber shaves himself if and only if the barber does not shave himself. As with self-reference,

2040-421: The collision must become its downfall. This, then, is the ultimate paradox of thought: to want to discover something that thought itself cannot think. A paradoxical reaction to a drug is the opposite of what one would expect, such as becoming agitated by a sedative or sedated by a stimulant . Some are common and are used regularly in medicine, such as the use of stimulants such as Adderall and Ritalin in

2100-438: The context or language in order to lose their paradoxical quality. Paradoxes that arise from apparently intelligible uses of language are often of interest to logicians and philosophers . "This sentence is false" is an example of the well-known liar paradox : it is a sentence that cannot be consistently interpreted as either true or false, because if it is known to be false, then it can be inferred that it must be true, and if it

2160-430: The distinction between decay of cured wood in construction, i.e. dry wood, versus decay of wood in living or newly felled trees, i.e. wet wood. 'Dry rot' is an 18th-century term that generally described what is now called brown rot . The term was used because the damage was present in cured or dried timber of ships and buildings and was thought to be caused by internal ‘fermentations’ rather than water. This contributes to

2220-633: The early 19th century the rapid increase in instances of timber decay attributed to dry rot (brown rot) in the British naval fleet brought the term into wider usage. Thomas Wade's 'A Treatise on the Dry Rot in Timber' was published posthumously by the Navy Office in 1815 following his investigation of the matter in ships from various countries. The second HMS  Queen Charlotte was launched in 1810 and, when inspected,

2280-419: The early periods of earth as macrofossils such as plants are not common nor well preserved. Both cryptospores and modern spores have diverse morphology that indicate possible environmental conditions of earlier periods of Earth and evolutionary relationships of plant species. Paradox A paradox is a logically self-contradictory statement or a statement that runs contrary to one's expectation. It

2340-434: The epoxy application is designed to shed water. Epoxy or other polymers will trap moisture behind the patch, causing more decay in the surrounding previously uninfected zones unless the repaired zone is protected from recurring water events. Commercial ethylene glycol (commonly sold as antifreeze ) and many other toxic diffusible compounds can diffuse into the wood to kill the fungus, but they also can diffuse out of wood that

2400-514: The extremities of the organism; not, as is sometimes inferred, to simply render dry timber wet enough to attack. Coggins goes into more detail about water movement in Serpula lacrymans . The perpetual saturation of wood with water also inhibits dry rot, as does perpetual dryness. Dry rot would appear to be a paradoxical term seemingly indicating decay of a substance by a fungus without the presence of water. However, its historical usage dates back to

2460-569: The fluids of the ascus that lead to explosive discharge of the ascospores into the air. The forcible discharge of single spores termed ballistospores involves formation of a small drop of water ( Buller's drop ), which upon contact with the spore leads to its projectile release with an initial acceleration of more than 10,000 g . Other fungi rely on alternative mechanisms for spore release, such as external mechanical forces, exemplified by puffballs . Attracting insects, such as flies, to fruiting structures, by virtue of their having lively colours and

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2520-735: The fusion of two haploid gamete cells. Among sporogenic dikaryotic cells, karyogamy (the fusion of the two haploid nuclei) occurs to produce a diploid cell. Diploid cells undergo meiosis to produce haploid spores. Spores can be classified in several ways such as by their spore producing structure, function, origin during life cycle, and mobility. Below is a table listing the mode of classification, name, identifying characteristic, examples, and images of different spore species. Under high magnification , spores often have complex patterns or ornamentation on their exterior surfaces. A specialized terminology has been developed to describe features of such patterns. Some markings represent apertures, places where

2580-426: The hosts through the pairing of two nuclei within the plasmodium, which develops from the amoebula. In plants, spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte . In some rare cases, diploid spore is also produced in some algae, or fungi. Under favourable conditions, the spore can develop into a new organism using mitotic division, producing

2640-449: The hyphae cause a significant increase in the moisture content of otherwise dry wood. Dry rot can be very difficult to remediate unless the timber is dried. In some cases after this is done, decayed areas can be treated with special epoxy formulations that fill-in the channels of the damaged wood, killing the rot and improving structural integrity. However, this type of treatment can actually promote decay in wood in exterior service unless

2700-491: The initial premise. In the case of that apparent paradox of a time-traveler killing his own grandfather, it is the inconsistency of defining the past to which he returns as being somehow different from the one that leads up to the future from which he begins his trip, but also insisting that he must have come to that past from the same future as the one that it leads up to. W. V. O. Quine (1962) distinguished between three classes of paradoxes: A veridical paradox produces

2760-503: The main one being Serpula lacrymans , in the majority of texts dealing with the subject, predominantly from the United Kingdom . This type of fungal decay subsequently also became known as 'true dry rot'. It has even been proposed to use the term water-conducting fungi in the category of brown rot rather than dry rot . However, although the fungi such as these can transport water, it is disputed that it can use this water to increase

2820-527: The mid-Ordovician (early Llanvirn, ~ 470  million years ago ), a period from which no macrofossils have yet been recovered. Individual trilete spores resembling those of modern cryptogamic plants first appeared in the fossil record at the end of the Ordovician period. In fungi, both asexual and sexual spores or sporangiospores of many fungal species are actively dispersed by forcible ejection from their reproductive structures. This ejection ensures exit of

2880-613: The moisture content of otherwise dry wood. Whilst it may be disputed as the citation notes, the epithet 'lacrymans' is derived from the Latin word ' lacrimare ', meaning 'to weep' and most surveyors of rotted buildings have noted the tear drops formed by the fungus as water forms on the hyphae. These water droplets are photographed in Rentokil 's book "Decay of Timber in Buildings" Figure 24. There is, however, no evidence these small amounts of water on

2940-519: The phenomenon. In modern texts, the term 'dry rot' is used in reference to damage inflicted by either: Serpula lacrymans (formerly Merulius lacrymans ) predominantly in the United Kingdom and northern Europe; and/or Meruliporia incrassata (which has a number of synonyms, including Poria incrassata and Serpula incrassata ) in North America . Both species of fungi cause brown rot decay, preferentially removing cellulose and hemicellulose from

3000-553: The regress or circularity is vicious . Again, the liar paradox is an instructive example: "This statement is false"—if the statement is true, then the statement is false, thereby making the statement true, thereby making the statement false, and so on. The barber paradox also exemplifies vicious circularity: The barber shaves those who do not shave themselves, so if the barber does not shave himself, then he shaves himself, then he does not shave himself, and so on. Other paradoxes involve false statements and half-truths ("'impossible'

3060-450: The remaining original surface is saturated with such a compound (typically green in color) before application of the new wood. In certain buildings, particularly those with solid 9 inch (or greater) brickwork and those built using lime mortar and flintstone , dry rot has been known to travel through and along the wall surface behind plaster and render. It is therefore recommended, by companies that sell this service, that where dry rot

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3120-399: The same size and type. Heterosporous plants, such as seed plants , spikemosses , quillworts , and ferns of the order Salviniales produce spores of two different sizes: the larger spore (megaspore) in effect functioning as a "female" spore and the smaller (microspore) functioning as a "male". Such plants typically give rise to the two kind of spores from within separate sporangia, either

3180-407: The spores from the reproductive structures as well as travelling through the air over long distances. Many fungi thereby possess specialized mechanical and physiological mechanisms as well as spore-surface structures, such as hydrophobins , for spore ejection. These mechanisms include, for example, forcible discharge of ascospores enabled by the structure of the ascus and accumulation of osmolytes in

3240-464: The term paradox is often used to describe a counterintuitive result. Self-reference , contradiction and infinite regress are core elements of many paradoxes. Other common elements include circular definitions , and confusion or equivocation between different levels of abstraction . Self-reference occurs when a sentence , idea or formula refers to itself. Although statements can be self referential without being paradoxical ("This statement

3300-432: The timber, leaving a brittle matrix of modified lignin . The term dry rot is somewhat misleading, as both species of fungi Serpula lacrymans and Meruliporia incrassata require an elevated moisture content to initiate an attack on timber (28–30%). Once established, the fungi can remain active in timber with a moisture content of more than 20%. At relative humidities below 86 percent, growth of Serpula lacrymans

3360-437: The timbers of the upper decks were found to be infected with 'the dry rot'. By 1816 the cost of repairs for this vessel had exceeded the ship's original construction cost. Texts published in the 19th and early 20th centuries also used the term to describe fungi which produced substantial (white-colored) mycelium, including Antrodia (Fibroporia) vaillantii . Eventually, the term dry rot came to apply to only one or two fungi

3420-418: The tough outer coat of the spore can be penetrated when germination occurs. Spores can be categorized based on the position and number of these markings and apertures. Alete spores show no lines. In monolete spores , there is a single narrow line (laesura) on the spore. Indicating the prior contact of two spores that eventually separated. In trilete spores , each spore shows three narrow lines radiating from

3480-399: The treatment of attention deficit hyperactivity disorder (also known as ADHD), while others are rare and can be dangerous as they are not expected, such as severe agitation from a benzodiazepine . The actions of antibodies on antigens can rarely take paradoxical turns in certain ways. One example is antibody-dependent enhancement (immune enhancement) of a disease's virulence; another

3540-419: The winter and placed in sheds or dry dock for repair. The boats already had some amount of rot occurring in the wood members, but the wood cellular structure was full of water making it still function structurally. As the wood dried out, the cell walls would crumble. In other words, the wood was already rotten and as the boat dried, the wood collapsed and crumbled, causing the workers in the yard to determine it

3600-712: Was "dry rot", when in fact, the wood had been rotten all along. Schilling & Jellison note the potential efficiency of these 'dry rot' fungi in growing away from direct moisture sources, although there is no reference for how efficient a brown rot fungus has to be at translocating water in order to be classed as 'dry rot'. Some have suggested the importance of these fungi providing their own source of nutrients as being more significant than providing an adequate source of moisture. Schilling suggests efficient nutrient translocation and utilization, notably nitrogen and iron, may be more distinctive in these species than water translocation. Water translocated in this fashion carries nutrients to

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